def edit_distance(word1: str, word2: str) -> float:
    """计算编辑距离"""
    m, n = len(word1), len(word2)
    dp = [[0] * (n + 1) for _ in range(m + 1)]

    for i in range(m + 1):
        dp[i][0] = i
    for j in range(n + 1):
        dp[0][j] = j

    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if word1[i - 1] == word2[j - 1]:
                dp[i][j] = dp[i - 1][j - 1]
            else:
                dp[i][j] = 1 + min(dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1])

    return dp[m][n]


if __name__ == "__main__":
    print(edit_distance("cat", "cut"))  # 输出: 1
    print(edit_distance("sunday", "saturday"))  # 输出: 3
    print(edit_distance("abcd", "efg"))  # 输出: 3
